The present invention relates to magnetic devices. More particularly, the present invention relates to a magnetic writer that includes a virtual front shield structure for improving the down-track field gradient of the magnetic writer.
Two general techniques for magnetically recording information on a storage medium include longitudinal recording and perpendicular recording. In longitudinal recording, the direction of the magnetization in the plane of the storage medium is altered in a manner to store information. In perpendicular recording, the magnetization of the storage medium is altered in a direction that is perpendicular to the plane of the medium. With the magnetization direction perpendicular to the plane of the medium as opposed to parallel with the plane, information can be stored at higher density.
There has been an ongoing effort to increase areal densities in magnetic recording. High areal densities can be achieved in a perpendicular recording system by increasing the linear and/or track densities. For high linear densities, the transition parameter of a bit transition, as well as the transition jitter, need to be minimized. The actual values of the transition parameter and the transition jitter will depend upon both the properties of the recording medium and the on-track field gradient of the write head. The write field gradient should approximate a step (i.e., an infinite slope of the field gradient) at the dynamic coercivity of the recording medium being used. In a similar manner, the track density that can be obtained will depend, in part, on the off-track field gradient of the write head.